Shin Ji-Eun, Kim Jong-Mi, Bae Eun-Ah, Hyun Yang-Jin, Kim Dong-Hyun
College of Pharmacy, Kyung Hee University, 1 Hoegi, Dongdaemun-ku, Seoul 130-701, Korea.
Planta Med. 2005 Mar;71(3):197-201. doi: 10.1055/s-2005-837816.
Flavonoids, which are main constituents of herbal medicines, have been reported to inhibit the growth of Helicobacter pylori (HP). Therefore, to evaluate the anti-HP activity of some flavonoids (flavanols, flavones, flavonols and isoflavonoids), their effects on the growth and vacuolation of HP as well as the infective properties of HP against HeLa cells were investigated. Catechins, quercetin and naringenin weakly inhibited the growth of HP, but all tested compounds did not inhibit HP infection into KATO III cells and HP urease activity. Quercetin and naringenin inhibited HP VacA vacuolation in HeLa cells with IC (50) values of 0.046 and 0.36 mM, respectively. Quercetin also inhibited procaspase-3 activation to caspase-3 in HeLa cells induced by HP VacA toxin, which may induce cell death via the proteolytic activation of a cascade of caspases. However, quercetin did not affect Bax and Bcl-2 protein levels. Based on these findings, quercetin may improve gastric cell death by inhibiting apoptotic signaling by HP VacA toxin. Abbreviations. HP: Helicobacter pyloriBSA:bovine serum albumin ESL:enhanced chemiluminescence MIC:minimum inhibitory concentration MTT:methylthiazolyldiphenyl-tetrazolium bromide PBS:phosphate-buffered saline VacA:Vacuolating cytotoxin.
黄酮类化合物是草药的主要成分，据报道其可抑制幽门螺杆菌（HP）的生长。因此，为了评估某些黄酮类化合物（黄烷醇、黄酮、黄酮醇和异黄酮）的抗HP活性，研究了它们对HP生长和空泡化以及HP对HeLa细胞感染特性的影响。儿茶素、槲皮素和柚皮素对HP生长的抑制作用较弱，但所有测试化合物均未抑制HP对KATO III细胞的感染及HP尿素酶活性。槲皮素和柚皮素可抑制HeLa细胞中HP VacA空泡化，IC（50）值分别为0.046和0.36 mM。槲皮素还可抑制HP VacA毒素诱导的HeLa细胞中procaspase-3向caspase-3的激活，这可能通过一系列半胱天冬酶的蛋白水解激活诱导细胞死亡。然而，槲皮素不影响Bax和Bcl-2蛋白水平。基于这些发现，槲皮素可能通过抑制HP VacA毒素的凋亡信号传导来改善胃细胞死亡。缩写：HP：幽门螺杆菌；BSA：牛血清白蛋白；ESL：增强化学发光；MIC：最低抑菌浓度；MTT：甲基噻唑基二苯基四氮唑溴盐；PBS：磷酸盐缓冲盐水；VacA：空泡毒素 。
